Field of the Invention
The present invention relates to a fuel storage system, and specifically, control of action of a fuel filler lid for a sealed fuel tank.
Description of the Related Art
In a prior-art technique to prevent fuel evaporative gas, produced within a fuel tank, from being emitted to the atmosphere, a sealing valve (tank shutoff valve) is fitted to a passage connecting a fuel tank to a canister to seal the fuel tank, and at the time of filling the fuel tank, the sealing valve is opened to allow fuel evaporative gas to flow from the fuel tank into the canister and become adsorbed within the canister.
When the fuel tank is sealed by the sealing valve as in the aforementioned system, an increase in ambient air temperature may lead to a high pressure in the fuel tank because of more fuel evaporating within the fuel tank, which may lead to fuel evaporative gas being emitted to the atmosphere at the time of opening the fuel filler lid to fill the fuel tank.
To prevent fuel evaporative gas from being emitted to the atmosphere at the time of filling the fuel tank, the sealing valve is opened upon detecting a driver's manipulation for opening the fuel filler lid, before the fuel filler lid is opened, to allow fuel evaporative gas to flow from the fuel tank into the canister, thereby decreasing the pressure in the fuel tank to a sufficiently low level in advance, and then, the fuel filler lid is opened (JP 2005-262905 A).
In the fuel storage system disclosed in the aforementioned publication, when the driver performs manipulation for opening the fuel filler lid, the pressure in the fuel tank is decreased and then the fuel filler lid is opened.
This means that in the fuel storage system disclosed in publication 1, once the driver performs manipulation for opening the fuel filler lid, the fuel filler lid is not opened until the pressure in the fuel tank decreases to a predetermined level.
For example, when washing a vehicle, if the pressure in the fuel tank is high, the fuel filler lid is opened to wipe moisture from the inner side of the fuel filler lid. In such case, if the pressure in the fuel tank is not easily relieved, it takes long time to decrease the pressure in fuel tank to a desired level, and thus, it takes long time until the fuel filler lid can be opened.
The driver's having to wait for a long time until the fuel filler lid is opened is inconvenient and undesirable.